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Author Topic:   Setting hydraulic valve lash
Rookieracer76
Member
posted March 28, 2004 04:59 PM
With the engine cold how can you set the valves with a hydraulic cam? also what is a good setting?(SBC).... thanks


waltonjr1
Member
posted March 28, 2004 06:11 PM
0 deg TDC, both number one valves shut.

Adjust the #1 exhaust valve

Adjust the #1 intake valve

Adjust the #3 exhaust valve

Adjust the #5 intake valve

Adjust the #7 intake valve

Adjust the #2 intake valve
Adjust the #4 exhaust valve
Adjust the #8 exhaust valve
Now rotate the engine 360 degrees. The mark on the balancer should be back at the TDC mark. Keep in mind that this is not the TDC where #1 would be firing! It's where #6 would fire.
Adjust the #3 intake valve
Adjust the #5 exhaust valve
Adjust the #7 exhaust valve
Adjust the #2 exhaust valve
Adjust the #4 intake valve
Adjust the #6 exhaust valve
Adjust the #6 intake valve
Adjust the #8 intake valve

To set the valve, back off the rocker until its completly loose. Roll the push rod with your fingers while you slowley tighten on the rocker nut. When the pushrod stops your at zero lash, go another 1/4 to one turn(depends on how close you are on vacumm) then repeat on each cyl.



racer17j
Member
posted March 28, 2004 07:07 PM
thats how i do it tighten it up till the pushrod stops rolling in your fingers then 1/4 turn pre load


joetaylor
Member
posted March 28, 2004 07:58 PM
it is all about preference I ran my figure eight car with 0 lash and tighen the poly locks down no 1/4 no 1/8 no 1/2 nothing 0 lash and ran roller springs anddidn't take the lobes off either

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U LIFT U LOOSE


racer17j
Member
posted March 29, 2004 08:01 PM
joe scroll down a few posts on here to another valve lash post and steve gives you the reason why you set that pre load in them


RangeRover
Member
posted March 30, 2004 06:34 AM
Where people may get confused is that you dont want to tighten it down while spinning it until you cant spin it anymore. When you just feel a slight resistance that is the zero lash point. It is easier to do with the intake off the first time but after you get the hang of it and a feel for the right resistance then you can do them with everything assembled.


RangeRover
Member
posted March 30, 2004 08:41 AM
What I should have said is, tighten the rocker until the pushrod wants to stop turning, not until it wont turn. Of course if you tighten it until it wont turn you may be to tight. Remember we are talking about hyd lifters here and you can go a whole turn on the nut after o lash, so if you think your zero lash is a little tighter than it should be, only go a 1/4 or 1/2 turn and you will be okay.


dirtbuster
Member
posted March 30, 2004 01:50 PM
I would reccomend doing it without the intake to start with and watch the plunger and spin the pushrod at the same time. That way you can get the feel of the spinning pushrod at zero lash. Yes the pushrod will still spin freely at zero but there is just a slight variation in resistance that can be felt with practice. Just like everything else it takes some practice, but really isnt difficult.


Rookieracer76
Member
posted April 07, 2004 07:56 PM
if i wanted to adjust them more accurate would i be able to use a feeler gauge if so what would be a good setting? thanks

[This message has been edited by Rookieracer76 (edited April 07, 2004).]

waltonjr1
Member
posted April 07, 2004 09:54 PM
You dont use a feeler gauge to set valves on a hyd cam b/c your going past zero lash. You only use feeler gauges to set valves with a solid cam.



tech355
Member
posted April 07, 2004 10:30 PM
most motor's and chilton book tell you how to do it, Best way is to do it with car running.


Limited Mod 57
Member
posted April 08, 2004 06:05 AM
77k, I too like to set them with the motor running, just it's difficult to hear them over the headers.

Rookie, I share your concern. It just seems there should be a more precise way to perform the check, as opposed to spinning them in our fingers.

One person may be able to grasp a rod tighter than another person; one pushrod may have more oil on it than another; etc.

And while I agree the better approach is to take the intake manifold off, that's too involved for frequent inspections.

But we may be splitting hairs here. And the "spinning them with our fingers" may get us close enough.

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[This message has been edited by Limited Mod 57 (edited April 09, 2004).]

dirtbuster
Member
posted April 08, 2004 08:07 AM
You cant use feeler guages because you arent leaving any lash in the vavletrain therefore there is no room for the feeler guage to measure anything. When done right it is actually pretty accurate plus thats what hyd lifters are for. They are self adjusting and will take care of themselves when you get them preloaded.

You really dont have to grip them that tight when spinning them. IF you can spin a pushrod between two fingers out of the motor then you can do it in the motor. Thats all that is required you dont need a lot of force. When the lash is gone there is just a slight resistance felt that is the point you need. It doenst take any more effort than spinning a pencil between 2 fingers. If your fingers are slipping and you cant grip tight enough then you have gone way too far.

waltonjr1
Member
posted April 08, 2004 11:31 AM
I agree dirtbuster, with hyd lifters its not as critical as most people make it out to be. All your doing is bringing the lifter down to about mid travel, then like you said they take care of their self from there.



77k
Member
posted April 09, 2004 02:19 AM
I use a stepescope to hear better.


racer17j
Member
posted April 09, 2004 04:05 PM
how do you keep the oil from running all oper the place and starting a fire with the covers off?


joetaylor
Member
posted April 09, 2004 04:09 PM
old valve cover with a hole cut to getacess to the polly locks werks 4 me

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U LIFT U LOOSE


77k
Member
posted April 09, 2004 11:05 PM
water and floor dry,after it cools a little, I spray headers with carb cleaner.


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